This invention generally relates to a latch assemblies. More particularly, the present invention is directed to a striker bar assembly as might be used with a latch to prevent the inadvertent forward folding of a motor vehicle seat back during sudden deceleration. The assembly includes a resiliently biased striker bar that assures proper alignment with the latch and permits deflection of the striker bar if inadvertently struck by another object.
As a safety feature, motor vehicle seat backs, which have forward folding capabilities, are often provided with an assembly that prevents the forwarding folding of the seat back when the vehicle is exposed to significant or sudden deceleration forces. These forces may occur, for example, during a frontal impact with another vehicle or during severe braking. In some vehicles, the rear seat back can be folded forward to provide access to a rear cargo space or to increased the load carrying area of the cargo space itself. In two door vehicles, the front seat backs can generally be folded forward to enhance rear seat ingress and egress.
Two broad types of assemblies are used for the above varieties of folding seats. Manual release assemblies require the operator to specifically actuate a spring biased latch lever before the seat can be folded forward. To increase operator convenience, most motor vehicle manufacturers now also provide inertia sensitive assemblies. The inertial assemblies typically permit the seat back to be freely folded forward. However, during vehicle deceleration above a pre-set level, the inertial assembly locks and prevents forward folding of the seat back.
These assemblies typically employ two individual mechanisms for securing the two separate bodies (the seat back and the support structure) together. The first of these mechanisms is a latch, either a manual or inertial release variety, and the second is a striker bar assembly.
The latch, mounted to the first body, releasably engages the striker bar assembly, mounted to the second body, thereby securing the two bodies together. In mounting the latch and the striker bar assemblies to their respective bodies, care must be taken to ensure that the hook portion of the latch is properly aligned with the cross member of the striker bar assembly. Failure to properly align the striker bar assembly and the latch can prevent engagement of the assembly. Since the latch and striker bar assembly are each mounted to support brackets of their respective bodies, which are in turn mounted to additional support structures, tolerance stackups often result in misalignment. If the misalignment is somewhat minor, it may only impact the smoothness of the assembly's operation. If the misalignment is severe, operation of the latch assembly may be completely impaired.
Previously, to correct misalignment, the striker bar assembly and/or the latch had to be removed and repositioned relative to each other. Obviously, the initial mounting of the latching, the inspection of the alignment between the latch and the striker bar assembly, and the realigning of the latch (or the striker bar assembly) are labor intensive operations that increase both production time and production cost.
Once properly mounted and aligned, if either of the mechanisms is inadvertently struck by a foreign object, misalignment may result. The mechanisms would then again need to be realigned.
With the above limitations in mind, it is a principal object of the present invention to provide an assembly that is operable when misaligned and requires no repositioning once it has been mounted. To this end, the present invention overcomes the problems of tolerance stack-up and allows the assembly to operate during both minor and relatively severe misalignment. Furthermore, the present invention allows for the striker bar assembly to deflect when struck by a foreign object and prevent misalignment for happening.
In achieving the above and other objects, the present invention provides an assembly in which the striker bar assembly is constructed in a manner which enables a cross member of the striker bar to self-align and positively locate itself relative to the latch lever of the latch and to deflect when struck by a foreign object. Three embodiments of the present invention are disclosed herein.
In the first embodiment, the striker bar includes the cross member and a cantilevered support member. The cantilever support member allows the cross member deflect upon contact with an engagement ramp of the latch. In response to this contact, deflection in a direction and an amount necessary to align the cross member with the hook of the latch's latch lever will occur.
The striker bar of the second embodiment includes a striker plate that defines the cross member. The striker plate is pivotally biased by a pair of tension springs. When misaligned, the striker plate will deflect, against the influence of the springs, when contacted by the engagement ramp of the latch into a position properly aligned relative to the hook of the latch's latch lever.
In a third embodiment of the present invention, a pivotally mounted striker plate is positioned by opposingly oriented torsion springs. The springs assure that the striker plate (and the cross member) is biased into a central or "dead center" position. A positive stop is utilized to ensure "dead center" positioning of the striker plate after deflection has occurred.
While the embodiments of the present invention are particularly suited for use in motor vehicles to restrict forward folding of seat backs, it is believed that the present invention has wider utility. For example, the present invention could readily be applied to vehicle doors, hoods and trunk lids, in addition to various non-motor vehicle latching applications. As will be seen from the discussion which follows, the present invention will find use in any latching situation where it is desirable to eliminate the need for precise mounting of the striker bar in relation to the latch or to permit the latch to recover from being inadvertently struck by a foreign object.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.